372 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. Z 



FURTHER NOTES ON THE APHIDIDAE COLLECTED IN 

 THE VICINITY OF STANFORD UNIVERSITY 



By W. M. Davidson 



In the Journal of Economic Entomology (Vol. II. No. 4, August^ 

 1909), I listed the Aphididae studied during a year's observation in 

 this region. During the year just passed I have continued my studies 

 on this family and am now able to increase considerably the number 

 of species tabulated in my former report. Mr. J. J. Davis (Annals 

 of the Ent. Soc. of America, Vol. I, 4 and II, 1) has lately reported 

 Callipterus {Pterocallis )tilice, an European insect, from America, 

 thus corroborating my inclusion of this species in my former paper. 

 I include a list of Aphididae so far reported from California. This 

 paper was prepared in the Entomological laboratories at Stanford 

 University. 



Phylloxera vastatrix Planchon. This species was formerly abundant 

 in California but of late years its numbers have diminished very 

 considerably. On Vitis. 



Chermes pinicorticis Fitch. This insect is often very destructive to 

 young trees, sometimes killing them. On Finns maritima. 



Chermes coiveni Gillette. I have taken this species on a young 

 Douglass spruce at Palo Alto. On April 13 of this year I noticed a 

 swarm of Lampyrid beetles (kindly determined for me by Mr. W. M. 

 Mann as Podabrus tomcntosus Say) flying around the aphids and at 

 times settling among them. Several times during the following week 

 I observed this same procedure, although in the morning the beetles 

 were always quietly feeding on the lice while in the evenings they 

 were very active and did not remain settled for more than a few 

 moments at a time. I counted one evening forty of the Lampyrids 

 at work. When disturbed they drop to the ground but recover them- 

 selves just before striking it and fly off. I have noticed a few of the 

 fire-flies attacking Lachnus occidentalis and Macrosiphum rosce, but 

 never in large numbers. 



Pemphigus betce Doane. On the roots of dock {Rumex occidentalis) 

 and of other related plants. 



Pemphigus populitransversus Kiley. This species was wrongly 

 called P. populicanlis in my former paper. Found in large numbers 

 on Populus trichocarpa. 



Pemphigus ranunculi sp. nov. Alate female (mounted in balsam). 

 Head, meso- and meta-thorax black. Prothorax olive. Antennae 



